Network Working Group Richard W. Watson
Request for Comments: 101 SRI-ARC
NIC: 5762 February 23, 1971
NOTES ON THE NETWORK WORKING GROUP MEETING
Wednesday Evening, February 17
Mike Sher opened by welcoming the group to Urbana and briefly
indicated that ILLIAC IV was expected to be running this summer. The
ILLIAC IV Project has been split into two projects; one on basic
system hardware and software, and the other on applications. Their
IMP is not yet connected to their PDP-11.
Steve Crocker asked for topics to be discussed at this meeting; these
are indicated below.
Peggy Karp of Mitre has been summarizing the old RFC's. She has a
list of about 30 topics and is summarizing their present status. She
expects to finish around the end of February. See RFC #100,
NIC(5761). It was suggested that someone write an RFC indicating
which ones are obsolete. It was also suggested that the Network
Information Center (NIC) help sites in organizing their hardcopy
There then followed brief discussions of experiences in using the
Network. John Melvin (SRI-ARC) summarized SRI's experience in using
the Utah PDP-10 to help in SRI's transfer from an XDS 940 to a PDP-
10. In April-May 1970 it was clear that SRI was headed toward a
PDP-10 in order to have the capacity and reliability to fulfill their
role as the Network Information Center. They had had some previous
experience in connecting with Utah, and so it seemed logical to try
to use the Utah 10 to aid the transfer.
In June use of the Network began. SRI uses higher level languages
extensively, so the first task was to transfer the compiler-
compiler Tree Meta. Source code was generated on the 940 to run
on the PDP-10. Binaries were then transmitted to Utah and run and
debugged. Patches were performed where possible, and source
changes accumulated. A new source and binaries would then be made
Once Tree Meta was running, a new high level language (called L-
10) for programming the On-Line System (NLS) was implemented in
the same way. When L-10 was running the core device independent
parts of NLS were rewritten and debugged. NLS was completely
reorganized during the transfer.
At the SRI and Utah ends a control program allowing three users to
connect to Utah was written, which ran as a user process and
allowed character interaction and files to be transmitted. The
scheme worked well and much useful work was accomplished in the
July--December period with some people on 4-5 hours per day. The
voice link was used when something would go wrong in trying to
determine where the problem existed and to reset. At times they
would go 2 weeks with no problems. SRI has an IMP interface
diagnostic which ran as a T/S process.
Generally, echoing was handled at the SRI end. DDT was used at
Utah end. Round trip character delays of 4 seconds were not
uncommon, and at certain points delays of 8 or 10 minutes were
experienced. These delays were the result of the implementation
used which involved multiple processes at each end, each to be
scheduled. Utah was heavily loaded at 2:00 PM and the SRI people
took to running at night and on weekends.
When the SRI PDP-10 came in in December, use of the Network
Users would have liked a more constant response time instead of
the widely varying one so that their work habits could adapt to it
even if it was slow.
Gerry Cole reported on some results of measurements made during the
SRI-Utah work. Measurements were also made at SRI to help in
interpreting the data obtained by UCLA. Gerry wrote a paper
summarizing these statistics which is available from him care of SDC.
Gerry requested that when people are set up to use the Network,
they inform him so that he can gather statistics. UCLA will
eventually have a program to scan the Network for utilization, but
if people could tell him when they were going to use the Network,
it would be easier to measure meaningful things and interpret the
data from a knowledge of type of usage.
Bob Kahn indicated that BBN is interested in the Statistics on
overall flow to see if the Network is configured properly. Gerry
said that UCLA is interested in the statistics for Network modeling
studies. Measurements are taken by remote control by use of a
feature designed into the IMP's by BBN for such a function.
Jim White of UCSB said that UCSB and RAND had begun to experiment in
use of the Network for the climate study at RAND. The UCSB NCP has
been up the last 3 or 4 weeks during the day. A document, NIC (5480)
is available in the NIC collection describing it. UCSB is also using
their NCP for local interprocess communication experiments. RAND is
using the Remote Job Entry facility of the UCSB 360-75. They are
using UCSB to check out their NCP. Now that UCSB is running their
NCP during normal usage hours, they have uncovered some bugs in their
hardware interface to their IMP. The software at both UCSB and RAND
seems to be working. Typical jobs being sent back and forth are just
test jobs of a few source statements. The UCSB NCP is about 39K
bytes and runs in a 60K byte partition. Users access it through
assembly language, Fortran or PL/I calls.
Steve Crocker now returned to the discussion of the agenda for the
meeting and longer range organization of the NWG. Steve felt that
Working committees on various topics were required as the open
meeting was good for bringing up problems, general discussion and
education, but was too large to prepare detailed specifications on
The following topics requiring work were listed:
2. Data Transformation Languages
3. Host-Host Protocol -- long range study
4. Host-Host Protocol -- Short term maintenance and modifications
6. Logger Protocol
7. Typewriter connection protocol
9. Data Management
In #1 Al Vezza of MIT is organizing an NWG meeting in graphics April
25-27 which can accommodate 31 people. People desiring to come
should prepare for their institution a working paper. Al sees three
classes of problems:
i) two hosts, each with computing and graphics facilities,
wanting to use special facilities at the other
ii) one host with graphic facilities but no number crunching
facilities wanting to use computing capabilities of a second host
iii) a node with a graphic terminal not having picture processing
or computing capability desiring to obtain these from other nodes.
With respect to #2 John Heafner of RAND indicated RAND wants to
provide data rearrangement services of the type indicated in RFC #83,
NIC (5621). More on this topic below.
With respect to #3 a group under A. N. Habermann of CMU has been
formed to look at the Host-Host protocol. Toward the end of March
they are planning a paper discussing their ideas. The group consists
A. N. Habermann, CMU
G. B. Hansen, CMU
W. Wulf, CMU
R. Chen, CMU
R. Kalin, Lincoln Lab
The group welcomes suggestions of topics.
With respect to #4 a group is to be set up to evaluate present
protocol and produce needed changes to the protocol. The group is to
be conservative and produce only changes needed to solve known
problems and leave esthetic changes until later.
With respect to the other problems discussion was put off until later
Two people interested in the Network who were observers at the
meeting spoke briefly.
C. D. (Terry) Shepard of the Computer Communication Task Force,
Canadian Government, outlined the goals of his group. These goals
1) establish a plan to link up various Canadian computers and
establish a network
2) develop what the needs of Canada are for such a network
3) see that the benefits of such a network are distributed
4) prevent control of computing in Canada from being totally
dependent on foreign sources.
5) see that critical computer facilities exist in Canada.
Doug McKay of IBM then described briefly a network project started
in IBM about 2 years ago. Basic network is completed. Users are
coming on. The network is to be used heavily to send files back
and forth for program updating. IBM is trying to look at the
network as a multiprocessor machine. They are trying to handle
all IBM system possibly heterogeneous such as 360's, 370's, CP '
67, the 91, a 44, and a NYU CDC 6600.
There is another project linking TSS systems using a 91 for remote
job entry. IBM has taken a centralized control point of view
using one central machine for control and flow distribution. They
are not entirely happy with this approach and are moving toward a
more decentralized approach like the ARPA Network. IBM presently
has about 14 people involved in the project.
Thursday morning, February 18
Thursday morning started with the various sites reporting their
status. Alex McKenzie of BBN prepared a status form later in the day
which was filled out by the representatives of the sites Thursday
evening. BBN and NIC will prepare a procedure for keeping this
information at the sites and up to date.
BBN, TENEX PROJECT: Final stage of incorporating NCP in TENEX. A
connection was attempted to Utah, but some bugs were found. The NCP
treats the network as a file in a way integral with other types of
files. The NCP includes a teletype interface. They hope to
incorporate the NCP in SRI'S TENEX system by the end of the month.
BBN, NETWORK GROUP: reported that they were working on three areas
1. Improving the current network
2. Working on a 316 version of the IMP and as a Terminal Interface
There are currently 15 IMPs connected to the network. A new software
system with minor changes is expected by March.
The TIMP uses the 316. A hardware design exists, but they are still
defining the software. A TIMP can handle up to 64 variable speed
terminals both sync and assync. The first machine is to go to MITRE
BBN emphasized that there are 3 products: a 516 IMP, a 316 IMP, and
a 316 TIMP. The 316 IMP is less expensive than the 516 IMP and can
connect to one host. BBN is not planning at the moment to exchange
316 IMPs for 516 IMPs. The two are plug-plug compatible.
SDC: In the debug phase for their NCP and expect it up in 4 to 6
weeks. Maybe by 8 weeks their T/S available for network use. Their
T/S is a 360/65 running the ADEPT system.
CASE WESTERN RESERVE UNIVERSITY: The IMP has been connected for
about one month, but as yet have no NCP. They are planning to use
the NCP implemented at Harvard. Case has a PDP-10/50 system. They
expect to be up in two to three months.
HARVARD: Harvard has a PDP-1 and PDP-10 connected to the IMP. The
NCP for the 10 is in final debugging. The PDP-1 is for refreshing
displays. The PDP-10 is for linguistic research and students.
Expect to be up in one to two months.
SRI-ARC: SRI has been in the final stage of conversion from an XDS
940 to a PDP-10. They plan to use the BBN TENEX NCP and should be up
in three or four weeks.
MIT DYNAMIC MODELING - PDP-10: They expect an NCP to be working by
MIT MULTICS: They are connected to the IMP and expect their NCP to
be in the final debug stage in four weeks. As Multics is a service
machine, they don't have unlimited access and must perform checkout
at off hours. They expect to offer regular service to the network in
three or four months.
UTAH: PDP-10/50 probably going to be running TENEX in the fall.
Their NCP is being written in a higher level language (Euler run
interpretively) and are debugging in conjunction with BBN. They have
connected to and logged into themselves and expect a debugged version
within a month.
LINCOLN LABORATORY, TX-2: They are testing the IMP interface, found
errors in Lincoln hardware. Currently, no data errors, but have
errors with message IDs. They expect their NCP with logger to be up
by April 15. They indicated that for testing purposes, they would
like to bring up their IMP without being open to network traffic.
BBN says that there is a way to echo to yourself without being open
to the network (contact BBN for details).
LINCOLN LABORATORY, 360/97: Running CP/CMS. The IMP interface was
completed last month. The NCP and Logger are working. They are
planning to put up the NCP as a regular service in April. On request
experiments with them can be run sooner.
UCSB: Has had their NCP since October. The NCP runs as independent
batch job. They plan to provide service to their On-Line System (a
manual is in the NIC collection at each site NIC (5480). They plan
to be on the air morning to evening on a regular basis. There are
some interface bugs as indicated earlier.
RAND: 360/65. Their NCP is a user process and can be resident. It
requires 8K bytes and does not have a logger.
UCLA, Sigma-7: Their NCP is in final debugging. They expect to be
up by March 1 with NCP, logger, and typewriter connection program.
COMPUTER CORPORATION OF AMERICA (CCA): Has just started a project to
create a node for the 10-12 bit laser store. They are going to use a
PDP-10 as a front end. They are developing a language for data
manipulation. The store will also be connected to the B-6500-ILLIAC
IV. They are planning data compression as part of their language to
ease the problems in use of the network's 50 kilobit line. They are
concentrating on security and privacy measures. Initial emphasis
will be on shared files. Installation is planned during 1972.
The following projects did not have representatives at the meeting.
Steve Crocker reported on their status.
CMU: PDP-10/50: Their IMP is connected, and they are planning to
use the Harvard NCP.
SRI-AI PROJECT: PDP10. They are planning to run TENEX in the
STANFORD-AI: They are not connected yet, but expect to be on by
The above completed the review of status. Steve Crocker then
indicated that the old NWG mailing list was no longer to be used and
that the list maintained by the NIC (5731,) was the one to be used or
that the NIC would handle distribution by sending things through your
station agent to them. If your station agent or liaison person
should change, please let the NIC know immediately.
HOST-HOST LOGGER PROTOCOL DISCUSSION: Tom Skinner of Multics opened
the discussion of the logger by indicating that they wanted at least
an interim protocol so that use of the network could get started.
They had handed out RFC #98 NIC(5744), containing their ideas
Wednesday night. SRI-ARC had a similar document, RFC #97, NIC
(5740), handed out Wednesday night also. Multics recommended the
revised logger protocol of RFC #80, NIC (5608).
Some discussion on the relative merits of the logger protocol of
RFC #66, NIC (5409), versus RFC #80 was given. The protocol of
#80 had some potential problems due to assumptions which must be
made after the initial contact was established.
The result of the discussion was that the logger protocol of RFC
#66 was adopted with the correction that the allocate commands
were to be issued after the connection was established.
There seemed to be a need for an official document to be issued
with the correct logger specification given.
Tom also recommended that initial communication to the logger be
in 7-bit ASCII in a 8-bit field. There was some discussion as to
whether the eighth bit should be a 0 or a 1. It was finally
decided that it should be a 0.
Steve then listed some known problems or questions about the
2) Message Type
5) Half Duplex vs. Full Duplex communication during the
establishing of a socket.
With regard to marking the following choices existed
a) leave alone
b) separate the heading and data into two messages
c) have message by multiples of 72 bits
With regard to interrupts (INS, INR), there was a synchronization
problem with regard to message transmission. That is, a message
could be sent and then an interrupt issued. The interrupt could
arrive before the message, in the middle of the message. Some way
of marking the point in the data stream where an interrupt was
sent is needed.
A subgroup was appointed to consider the above Host-Host problems.
Shortly, they would issue an RFC with modifications to the Host-Host
protocol, then collect comments and then issue an official revision.
People with suggestions should contact the committee. The committee
would also be contacting the sites. The committee is:
S. Crocker, UCLA (Chairman)
R. Tomlinson, BBN
T. Barkalow, Lincoln Lab
G. Grossman, University of Illinois
J. White, UCSB
R. Bressler, MIT, Project MAC
The discussion then returned to problems of typewriter access to the
network. The problems are presented in RFC #97, NIC (5740). Some
a) Character set
b) End of Line
d) Message Format
e) Half Duplex, Full Duplex
These problems were given to a committee on typewriter connection
protocol for solution:
Tom O'Sullivan, Raytheon (Chairman)
Ed Meyer, MIT-MAC
John Melvin, SRI-ARC
Bob Long, SDC
Bob Metcalfe, Harvard
Wil Crowther, BBN
This committee will come up quickly (within a week) with an interim
protocol and within several weeks a longer term protocol.
Thursday afternoon, February 18
Thursday afternoon was open to a presentation by the University of
Illinois on the ILLIAC IV and a demonstration of the Plato project.
The initial test in November of the transmission lines to the ILLIAC
IV processors indicated no timing problems. The ILLIAC IV hardware
is to be up the fall as is the software. The system will be located
in California at NASA Ames Research Center. The connection to the
network from the University of Illinois will be a PDP-11 with storage
CRTs, 2400 baud character CRTs, typewriters attached. It will have a
Gould Clevite printer, DECtapes and small disc. The B6500 at the
University will also be connected to the Network.
Thursday evening, February 18
The initial topic was a discussion of status and plans for the
Network Information Center. Dick Watson of SRI reviewed the present
off-line system consisting of a Station Agent and Network Liaison
person. The function of the Station Agent is to aid in the use of
the NIC services. The function of the Network Liaison person is to
be a point of contact for technical questions about his site which
may be asked by people at other sites, and to see that the
appropriate people see relevant documents and information received by
the site. If the network is really going to develop the feeling of a
community, people need to be aware of what people are doing and
thinking at the various sites. Therefore, people were encouraged to
send reports, memos, notes, records of conversations of general
interest through the NIC. Any kind of information can be sent
through the NIC from formal reports to informal handwritten notes.
In order to encourage people to send out initial thoughts and ideas
as well as those having had much thought, the question was raised as
to whether of not there should be titles for different classes of
documents which would help to make clear the level of informality or
formality of the communication.
There did not seem to be a need for such an arrangement. The
question of privacy and security was then raised. There was some
feeling among a few people that if letters or records of
conversations were entered in the NIC collection that there might
be compromise of some privacy. The NIC was asked if it would
check all parties involved in such a communication before entering
it in the collection. Dick felt that given NIC's resources, it
would be better if the parties involved gave their approval before
giving the letter or other communication to the NIC.
The initial online services to be provided by the NIC are access
to a typewriter version of the SRI-ARC On-Line system (NLS),
provision of a message service, access to the NIC catalog and
probably files of site status, network personnel, etc. Services
will be provided later to aid station agents in communities at
their sites. At the principal investigators meeting there seemed
to be considerable interest in having NIC obtain a collection of
ARPA project reports and working papers. To handle storage from
such an expanded collection, user of microfilm seemed important.
There are number of problems with use of microfilm, such as a
single or limited number of readers and need for hardcopy
facilities. The NIC will be looking into these problems and begin
experimenting with use of microfilm material.
The NIC is experimenting with remote access to NLS using an IMLAC
terminal. Considerable interest in graphic access to NIC was
indicated. The NIC feels graphic access is not an immediate high
priority requirement, but will as soon as possible provide
specifications to those sites with programming resources waiting
to experiment with graphic access.
Steve Crocker brought up the problem of how people are to gain
access and learn to use service facilities at various sites. The
question of what additional information needed to be included with
or appended to user documentation to use service facilities over
the network was discussed. The question of what material should
be in hardcopy, and what online was raised. The NIC will study
these problems and produce a set of recommended procedures for
handling user manuals, and a list of information needed to enable
Dick Watson indicated that users of the NIC would feel most
comfortable using typewriter terminals running at 30 char/sec and
having upper and lower case graphics, although service would be
available for slower terminals and terminals with single-case
graphics. RFC #97, NIC (5740), described an initial protocol for
connection to the NIC. As a result of the formation of a
committee to produce a standard typewriter connection protocol,
the protocol of RFC #97 will be modified to conform to an interim
protocol suggested by that committee. A new RFC will be issued
shortly with the interim protocol. Since the meeting the
typewriter connection protocol committee has decided not to issue
an interim protocol.
The discussion turned to file transfer between sites by name and
without users being required to log into each site involved in the
transfer. Gary Grossman of the University of Illinois will produce
an initial RFC on this subject.
Friday morning, February 19
There are several aspects of Data Management associated with the
network. The following aspects and the people responsible for them
Data Machine 10^12 bit store
Data Management Language
The Form Machine
ILLIAC IV Information Management System
Interim File System
File Transfer Protocol
The Data Machine is Computer Corporation of America's responsibility,
but close coordination with the ILLIAC IV Information Management
System and network efforts toward a Data Management Language is
The work on a Data Management Language is to be coordinated by J.
Madden of University of Illinois, Bob Metcalfe of Harvard, J. Heafner
of RAND, Jim White of UCSB, and Doug McKay of IBM.
John Heafner indicated that he plans to implement his plans for the
Form Machine, RFC #83, NIC (5609) UCSB, Multics, and Lincoln Lab also
indicated that they are interested in getting a version running.
A number of sites, UCLA, SRI, RAND, University of Illinois, Raytheon,
MITRE, indicated interest in the range 1-3 months in storing files on
UCSB 360/75 disc packs. Jim White said he would produce a system
within the next 4-6 weeks to allow network users to store files at
The problems of file transfer by name between host systems was again
raised and G. Grossman of University of Illinois indicated he would
start a dialog on the subject by producing an RFC.
The question of user names and the meaning of user IDs in socket
numbers was raised. At present socket numbers have no structure, but
several people felt that for accounting, file transfer, and
interprocess communication some structure was probably valuable. A
committee consisting of:
J. Heafner, RAND (chairman)
E. Meyer, MIT-Multics
G. Grossman, University of Illinois
will produce an RFC stating the issues behind alternate proposals for
socket number structures.
UCLA indicated it wanted a link number in the experimental range of
link numbers for use in measurements experiments with the network.
Link number 223 was assigned to this function. (Link 223 was later
discovered to be assigned. Link 191 was chosen instead. See RFC
#104, NIC (5768,).
The problem of accounting was raised as a number of machine or
systems on the network will provide service functions. The present
service facilities being the 360/91 at UCLA, the 360/75 at UCSB, the
NIC at SRI, Multics at MIT, the ILLIAC IV, the 360/67 at Lincoln Lab,
and the Data Machine. The advanced Host-Host protocol study
committee is looking at the accounting problem. There was brief
mention made of a network banking system. Bob Kahn of BBN indicated
that he would start a dialog on the subject of accounting by
producing a paper putting down the issues as he sees them.
The question was then raised about handling of administrative
procedures such as obtaining accounting numbers on foreign systems.
Dick Watson said he would look into this problem and see how the NIC
can help in its solution.
The final question to be considered was the frequency and utility of
these NWG meetings. The general consensus was that this had been a
useful meeting, but that more preparation on specific topics to be
discussed at the meeting should be done ahead of time. People who
want to bring up topics at the meeting were asked to distribute
position or introductory papers about a month ahead of the next
meeting, if possible. Peggy Karp will handle trying to obtain a
block of rooms for the NWG during the Spring Joint. She will send
out a request for reservations to the sites soon.
[This RFC was put into machine readable form for entry]
[into the online RFC archives by Kelly Tardif, Viagénie 10/99]